1. Field of the Invention
The present invention relates to a method of working (or fabricating) a press die in which a specific portion of the press die is formed or made of a material which is different from a die main body.
2. Description of the Related Art
As a press die, e.g., a trimming die having a blade portion for cutting a blank plate, there is conventionally known one in which the blade portion is formed of a material which is higher in hardness than a main body of the press die.
In manufacturing this kind of trimming die, the following steps are employed Namely, a blank for a trimming die (also called a die blank) is subjected to profiling (ice., machining for profiling purpose) Also, that edge portion of the die blank which corresponds to the blade portion of the trimming die is cut to thereby form a beveled or chamfered portion. This beveled portion is then clad or overlaid with a material that is used for forming the blade portion by means of arc welding or the like. This clad portion is thereafter worked or machined into a predetermined shape to thereby form the blade portion.
In this case, it is normal practice to transfer the die blank, after the beveled portion has been formed, from a working apparatus to a welding machine to thereby perform the cladding work, and thereafter to return the die blank back again to the working apparatus to thereby perform the working or machining of the clad portion.
The above-described method has a disadvantage in that the transfer of the die blank between the working apparatus and the welding machine takes much time, with the result that the productive efficiency is lowered.
In view of the above-described point, the present invention has an object of providing a method of working a press die in which the necessity of transferring of the die blank has been eliminated and which is therefore high in productive efficiency.